The Analysis of Variance in a Sampling Experiment

A complete set of equations is given for computing the various “sums of squares” of deviations about the several means of an experiment involving a number of increments of varying weight, taken in close order within groups but with an appreciable interval between groups. Methods of determining the sampling constants σi2 and σt2 (the “unit increment” and “trend” variances, respectively, are given, together with the method of determining the significance of σt2. The equation relating these sampling constants to the observed variance of gross samples of N increments of weight w (as collected) is also given.

An appendix considers a “short cut” method of eliminating the effect of errors of “reduction and analysis” from the “crude estimates” of σi2 and σt2.